Understanding fault activity over time provides valuable insights for reconstructing the tectonic history of an orogen,assessing seismological risks and understanding mineralization processes.In the Western Alps,one o...Understanding fault activity over time provides valuable insights for reconstructing the tectonic history of an orogen,assessing seismological risks and understanding mineralization processes.In the Western Alps,one of the main controversies in existing tectonic models is the understanding of syn-orogenic extension.Seismological evidence shows widespread extensional deformation related to the reactivation of major lithospheric structures,such as the Penninic Frontal Thrust(PFT).However,the onset age and origin of extension are still debated due to the lack of suitable geochronological data.Fault hematite and calcite geochronology as well as clumped isotope data can be used to relate fluid regimes to fault activity.The analysis of calcite brecciae from extensional faults above the PFT shows that two distinct fluid regimes were present.The first regime,occurring before 2 Ma is associated with upwelling of deep fluids and is recorded by fault calcite at a temperature>110°C.The second fluid regime is characterized by a meteoric signature and temperatures around 36°C,representing crystallization since 2 Ma.This study presents a new model for the Miocene tectonic history of the Western Alps that combines(U-Th)/He and U-Pb geochronology on fault hematite(13.3±0.8 to<0.8 Ma)and calcite(5.3±0.6 Ma).Results demonstrate a progression of extensional fault activity from east to west,from the Middle Miocene(ca.13 Ma)to the Quaternary.The onset of extension in the inner part of the belt coincides with the development of the fold and thrust belt in the western Alpine foreland.Our new model proposes that extension occurs in the hanging wall of a large top-to-the-west thrust,known as the Alpine Frontal Thrust.This thrust,located to the west of the External Crystalline Massifs gives rise to their uplifting and extension at the rear.展开更多
In this study,various chemical treatments were performed on clay-rich media to investigate their effects on hydrogen adsorption performance.We unequivocally demonstrated that acid-treated samples exhibited signifi-can...In this study,various chemical treatments were performed on clay-rich media to investigate their effects on hydrogen adsorption performance.We unequivocally demonstrated that acid-treated samples exhibited signifi-cant structural changes compared with those treated with alkali solutions.Gas adsorption isotherms and powder X-ray diffraction analyses clearly revealed that the acid treatment of clayey materials not only increased their surface area,but also enhanced hydrogen sorption uptake,increased interstratification,and reduced particle size.Most importantly,we succeeded in rationalizing the improvement in hydrogen uptake by sequentially applying purification,followed by acid treatment.展开更多
基金This work forms part of the first author’s Ph.D.project funded by the French BRGM in the frame of the RGF-Alps program(Référentiel Géologique de la France)The LA-ICP-MS hosted by the ENVITOP platform at CEREGE has received funding from the“Excellence Initiative”of the Aix Marseille University A*MIDEX–project DATCARB,a french“Investissement d’avenir”programSpecial thanks to Fayçal Soufi and Pierre-Luigi Canepa for their preparation of polished thin-section。
文摘Understanding fault activity over time provides valuable insights for reconstructing the tectonic history of an orogen,assessing seismological risks and understanding mineralization processes.In the Western Alps,one of the main controversies in existing tectonic models is the understanding of syn-orogenic extension.Seismological evidence shows widespread extensional deformation related to the reactivation of major lithospheric structures,such as the Penninic Frontal Thrust(PFT).However,the onset age and origin of extension are still debated due to the lack of suitable geochronological data.Fault hematite and calcite geochronology as well as clumped isotope data can be used to relate fluid regimes to fault activity.The analysis of calcite brecciae from extensional faults above the PFT shows that two distinct fluid regimes were present.The first regime,occurring before 2 Ma is associated with upwelling of deep fluids and is recorded by fault calcite at a temperature>110°C.The second fluid regime is characterized by a meteoric signature and temperatures around 36°C,representing crystallization since 2 Ma.This study presents a new model for the Miocene tectonic history of the Western Alps that combines(U-Th)/He and U-Pb geochronology on fault hematite(13.3±0.8 to<0.8 Ma)and calcite(5.3±0.6 Ma).Results demonstrate a progression of extensional fault activity from east to west,from the Middle Miocene(ca.13 Ma)to the Quaternary.The onset of extension in the inner part of the belt coincides with the development of the fold and thrust belt in the western Alpine foreland.Our new model proposes that extension occurs in the hanging wall of a large top-to-the-west thrust,known as the Alpine Frontal Thrust.This thrust,located to the west of the External Crystalline Massifs gives rise to their uplifting and extension at the rear.
基金supported by the European joint pro-gram on radioactive waste management for financial support(Grant ID:847593)for the project titled Hydrogen(H 2)Uptake and Physisorp-tion Mechanism in Micro-and Nano-porous Systems Application to Clayrock-hosted Nuclear Waste Repositories.M.R.T acknowledges Uni-versitéGrenoble Alpes,Institut des Sciences de la Terre(ISTerre),and eurad for supporting a postdoctoral fellowship.
文摘In this study,various chemical treatments were performed on clay-rich media to investigate their effects on hydrogen adsorption performance.We unequivocally demonstrated that acid-treated samples exhibited signifi-cant structural changes compared with those treated with alkali solutions.Gas adsorption isotherms and powder X-ray diffraction analyses clearly revealed that the acid treatment of clayey materials not only increased their surface area,but also enhanced hydrogen sorption uptake,increased interstratification,and reduced particle size.Most importantly,we succeeded in rationalizing the improvement in hydrogen uptake by sequentially applying purification,followed by acid treatment.
